Case 2: using cgi.force_redirect

The configuration directive cgi.force_redirect
prevents anyone from calling PHP
directly with a URL like http://my.host/cgi-bin/php/secretdir/script.php.
Instead, PHP will only parse in this mode if it has gone through
a web server redirect rule.
PHP older than 4.2.0 used --enable-force-cgi-redirect
compile time option for this.

Usually the redirection in the Apache configuration is done with
the following directives:

Action php-script /cgi-bin/php
AddHandler php-script .php

This option has only been tested with the Apache web server, and
relies on Apache to set the non-standard CGI environment variable
REDIRECT_STATUS on redirected requests. If your
web server does not support any way of telling if the request is
direct or redirected, you cannot use this option and you must use
one of the other ways of running the CGI version documented
here.

It appears that as of 5.3.0, --enable-force-cgi-redirect is not a valid configure option. A quick review of the 5.3.0 code indicates that it the logic previously enabled by specifying the --enable-force-cgi-redirect configure option is being built into php by default.